Transistors fabricated using the single crystals of [8]phenacene

Field-effect transistors (FETs) with single crystals of a new phenacene-type molecule, [8]phenacene, were fabricated and characterized. This new molecule consists of a phenacene core of eight benzene rings, with an extended ?-conjugated system, which was recently synthesized for use in an FET by our group. The FET characteristics of an [8]phenacene single-crystal FET with SiO<inf>2</inf> gate dielectrics show typical p-channel properties with an average field-effect mobility, ???, as high as 3(2) cm² V^-1 s^-1 in two-terminal measurement mode, which is a relatively high value for a p-channel single-crystal FET. The ??? was determined to be 6(2) cm² V^-1 s^-1 in four-terminal measurement mode. Low-voltage operation was achieved with PbZr<inf>0.52</inf>Ti<inf>0.48</inf>O<inf>3</inf> (PZT) as the gate dielectric, and an electric-double-layer (EDL) capacitor. The ??? and average values of absolute threshold voltage, ?|V<inf>th</inf>|?, were 1.6(4) cm² V^-1 s^-1 and 5(1) V, respectively, for PZT, and 4(2) × 10^-1 cm² V^-1 s^-1 and 2.38(4) V, respectively, for the EDL capacitor; these values were evaluated in two-terminal measurement mode. The inverter circuit was fabricated using [8]phenacene and N,N?-1H,1H-perfluorobutyldicyanoperylene-carboxydi-imide single-crystal FETs. This is the first logic gate circuit using phenacene molecules. Furthermore, the relationship between ? and the number of benzene rings was clarified based on this study and the previous studies on phenacene single-crystal FETs.